PitStopUSA.com - Air/Fuel Ratio Gauges

An airfuel ratio gauge monitors the airfuel ratio of an internal combustion engine. Also called airfuel meter, or airfuel gauge. It reads the voltage output of an oxygen sensor, sometimes also called lambda sensor, whether it be from a narrow band or wide band oxygen sensor. There are wide-band meters that stand alone or are mounted in housings. Nearly all of these show the airfuel ratio on a numeric display, since the wide-band sensors provide a much more accurate reading. And since they use more accurate electronics, these meters are more expensive.